Treatment method of high-nickel high-PGM anode slime

Abstract

The invention discloses a treatment method of high-nickel and high-PGM anode slime, which comprises the following steps: mixing the high-nickel and high-PGM anode slime with dilute sulphuric acid, pressurizing and heating, simultaneously introducing oxygen into the mixed solution, carrying out oxidation treatment, dissolving copper and nickel elements in the mixed solution, and after the reaction is finished, carrying out solid-liquid separation to obtain copper and nickel removed leaching solution and copper and nickel removed leaching residues; the copper and nickel removed leaching residues are smelted and blown, when the content of precious metal in the copper and nickel removed leaching residues is larger than or equal to 98%, water quenching treatment is conducted on the copper and nickel removed leaching residues, and a granulated alloy material is obtained; the granulated alloy material is subjected to chlorination leaching, and silver chloride and silver separation filtrate are obtained; the silver chloride is subjected to pyrogenic process reduction smelting and cast into a silver anode plate which is used for preparing silver powder through electrolytic refining; the silver separation filtrate is subjected to chlorination and acid leaching treatment till the silver content in the silver separation filtrate is smaller than 0.1%, then gold separation treatment is conducted on the silver separation filtrate, and gold sand and precious metal concentrate are obtained; and the precious metal concentrate is purified, and high-purity gold, platinum and palladium are prepared.

Description

Technical Field

[0001] The present invention belongs to the field of pyrometallurgy, and particularly relates to a method for treating high-nickel and high-PGM anode slime. Background Art

[0002] The statements herein only provide background art related to the present invention and do not necessarily constitute prior art.

[0003] High-nickel and high-PGM (PGM is a platinum group metal alloy, which is a collective term for alloys of 6 elements: ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and platinum (Pt)) anode slime is produced during the process of electrolytic refining of high-purity cathode copper from the crude copper produced by pyrometallurgical refining of concentrates containing high nickel and high PGM. This material contains relatively high contents of heavy metal element nickel and precious metal elements such as gold, silver, platinum, and palladium, and has a large difference in composition from the copper anode slime produced during the conventional copper smelting process.

[0004] Currently, the mainstream process for extracting precious metal elements from copper anode slime is to leach and remove copper through acid leaching, and then treat the leaching residue with a Kaldo furnace to prepare Dore alloy. The Dore alloy is used as a silver anode plate for electrolytic production of high-purity silver powder. The produced silver anode slime is treated to recover gold, and the PGM concentrate material produced after gold parting is treated to prepare precious metal products such as platinum, palladium, and rhodium. This process has relatively high requirements for the composition of precious metal alloys during the use of Dore alloy plates for electrolytic silver and the PGM treatment process (where the total content of gold and silver components in the Dore alloy used for electrolytic silver is greater than 98%), and cannot be applied to treat high-nickel and high-PGM anode slime raw materials. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a method for treating high-nickel and high-PGM anode slime.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0007] The present invention provides a method for treating high-nickel and high-PGM anode slime, including the following steps:

[0008] Mix the high-nickel and high-PGM anode slime with dilute sulfuric acid, then apply pressure and heat, and at the same time introduce oxygen into the mixed solution for oxidation treatment to dissolve the copper and nickel elements therein. After the reaction is completed, perform solid-liquid separation to obtain a copper and nickel removed leaching solution and a copper and nickel removed leaching residue;

[0009] Smelt and convert the copper and nickel removed leaching residue. When the precious metal content therein ≥ 98%, perform water quenching treatment on it to obtain granulated alloy material;

[0010] Perform chlorination leaching on the granulated alloy material to obtain silver chloride and a silver parting filtrate;

[0011] The silver chloride is subjected to pyrometallurgical reduction smelting and cast into a silver anode plate for electrolytic refining to prepare silver powder;

[0012] The silver separation filtrate is subjected to chlorination acid leaching until the silver content in the silver separation filtrate is <0.1%, and then it is subjected to gold separation treatment to obtain gold sand and precious metal concentrate;

[0013] The precious metal concentrate is purified to obtain high-purity gold, platinum, and palladium.

[0014] In the present invention, for the high-nickel and high-PGM anode slime, copper and nickel in the high-nickel and high-PGM anode slime are first leached by acid leaching, and then precious metal elements are enriched from the leaching residue by pyrometallurgical smelting methods to prepare a precious metal alloy containing elements such as gold, silver, platinum, and palladium. The alloy is subjected to water quenching treatment in a molten state and then subjected to chlorination leaching to separate the precious metal element silver and other precious metal elements. The silver is cast into a silver anode plate for electrolytic refining, and the leaching solution after silver separation is treated to extract gold and PGM. This method effectively recovers the precious metal elements in the high-nickel and high-PGM anode slime, effectively solves the problem that the precious metal alloy produced by the Kaldo furnace cannot be directly used as a silver anode plate, and indirectly expands the material processing capacity of the Kaldo furnace

[0015] In some embodiments, the concentration of the dilute sulfuric acid is 300-450 g / l.

[0016] In some embodiments, the temperature of the oxidation treatment is 140-170 °C, the pressure is 0.7-0.9 MPa, and the time is 10-20 h.

[0017] In some embodiments, the temperature of the smelting is 900-1000 °C, the time is 2-6 h, and when the smelting slag contains <0.2% Ag, slag discharging treatment is started;

[0018] The temperature of the blowing is 1100-1200 °C, and the time is 2-8 h.

[0019] In some embodiments, the copper- and nickel-free leaching solution is used to prepare crude nickel sulfate to ensure the recycling of metallic nickel.

[0020] Preferably, the method for preparing crude nickel sulfate using the copper- and nickel-free leaching solution is: cooling and crystallizing the copper- and nickel-free leaching solution to separate and recover nickel sulfate.

[0021] In some embodiments, the temperature of the water for water quenching is 0-40 °C.

[0022] In some embodiments, the specific method for chlorination leaching of the granulated alloy material is as follows: subject the granulated alloy material to chlorination leaching with a liquid-solid ratio of 6-8:1, an acidity of 2-3 mol / L, a sodium chlorate addition amount of 12-18% of the weight of the alloy material, a leaching solution temperature of 75-90 °C, and a hydrochloric acid concentration of 25-32%. Stir the whole process to obtain silver chloride and a silver separation filtrate, and the silver content in the silver separation filtrate after chlorination acid leaching is <0.1%.

[0023] In some embodiments, the method for pyro-reduction smelting of the silver chloride is as follows: add sodium carbonate and iron powder to the silver chloride, mix evenly, and carry out reduction smelting at a furnace temperature of 1050-1250 °C. The silver chloride is reduced to metallic silver, and other impurity elements enter the slag and float on the metal liquid surface.

[0024] In some embodiments, the silver anode slime generated after electrolytic refining of the silver anode plate to prepare silver powder is recycled into the alloy material after water quenching.

[0025] In some embodiments, the gold separation treatment method uses chlorination gold separation method.

[0026] The beneficial effects obtained from one or more of the above embodiments of the present invention are as follows:

[0027] (1) The leaching solution after leaching the high-nickel and high-PGM anode slime can be used to prepare crude nickel sulfate products, ensuring the recycling of metallic nickel;

[0028] (2) The water quenching process is adopted to prepare precious metal alloy particles, improving the efficiency of chlorination acid leaching of precious metal alloys;

[0029] (3) By reducing and smelting and casting silver anode plates after chlorination silver separation, the problem that the precious metal alloy plate produced by the Kaldo furnace cannot be directly used as a silver anode plate (when treating this kind of anode slime with the Kaldo furnace, the produced precious metal alloy plate contains a large amount of PGM elements, and the total content of gold and silver components is far less than 98%, which cannot meet the requirements of silver electrolysis) is solved, effectively improving the processing capacity of the Kaldo furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0031] Figure 1 It is the overall process flow chart of the embodiments of the present invention. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed description is illustrative and aims to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains.

[0033] The present invention will be further described below in conjunction with embodiments.

[0034] Embodiment 1

[0035] As Figure 1 shown, a method for treating high-nickel and high-PGM anode slime is specifically operated as follows:

[0036] (1) A dilute sulfuric acid solution with a concentration of 450 g / l and pre-leached anode slime are placed in an autoclave according to a liquid-solid ratio of 4:1, pressurized and heated. The temperature is 150 °C, the pressure is 0.9 MPa, and oxygen is introduced as an oxidant. The oxygen flow rate is 30 Nm 3 / h to dissolve elements such as copper and nickel in the anode slime. The obtained slurry is filtered to obtain a leachate and a copper-nickel removed leaching residue. The leachate enters the crude nickel sulfate preparation process system, and the leachate is cooled and crystallized to separate and recover nickel sulfate;

[0037] (2) The copper-nickel removed leaching residue in step (1) is added to a Kaldo furnace for smelting and converting reactions; the smelting temperature is 1000 °C and the time is 4 h. When the silver content in the smelting slag is <0.2%, slag discharging treatment starts; the converting temperature is 1100 °C and the converting time is 6 h;

[0038] (3) When the noble metal alloy content in the molten state is ≥98% and the content of other impurities Cu + Ni is <2% during the pyrometallurgical process in step (2), the molten noble metal alloy is subjected to water quenching treatment, and the temperature of the water used for water quenching is 10 °C;

[0039] (4) After the water quenching in step (3) is completed, the granulated alloy material is subjected to chlorination leaching to obtain silver chloride and a silver separating filtrate. After chlorination acid leaching, the silver content in the silver separating filtrate is <0.1%;

[0040] The specific method of chlorination leaching is as follows: The granulated alloy material is subjected to chlorination leaching with a liquid-solid ratio of 8:1, an acidity of 3 mol / L, a sodium chlorate addition amount of 12% of the weight of the alloy material, a leachate temperature of 90 °C, and stirring is carried out throughout the process;

[0041] (5) The silver chloride produced in step (4) is subjected to pyrometallurgical reduction smelting and cast into a silver anode plate, and further electrolytic refining is carried out to prepare silver powder, and the silver anode slime is returned to the alloy material after water quenching;

[0042] The method for fire reduction smelting of the silver chloride is as follows: Sodium carbonate and iron powder are added to the silver chloride, and the mass ratio of silver chloride, sodium carbonate and iron powder is 5:2:1. After mixing evenly, reduction smelting is carried out at a furnace temperature of 1250 °C. The silver chloride is reduced to metallic silver, and other impurity elements enter the slag and float on the metal liquid surface;

[0043] (6) The silver separation filtrate produced in step (5) is subjected to gold separation treatment to prepare gold sand and precious metal concentrates containing platinum, palladium, etc. respectively, and further purified to prepare high-purity gold, platinum, and palladium products.

[0044] After water quenching and granulation, the precious metal alloy becomes granular material. Compared with the large-piece precious metal alloy produced by the non-water quenching process, in the hydrochloric acid solution, the contact area between the alloy and the solution is increased, and the reaction rate is improved.

[0045] Example 2

[0046] A method for treating high-nickel and high-PGM anode slime is specifically operated as follows:

[0047] (1) A dilute sulfuric acid solution with a concentration of 350 g / l and pre-leached anode slime are placed in an autoclave according to a liquid-solid ratio of 5:1, pressurized and heated. The temperature is 170 °C, the pressure is 0.7 MPa, and oxygen is introduced as an oxidant. The oxygen flow rate is 40 Nm 3 / h to dissolve elements such as copper and nickel in the anode slime. The obtained slurry is filtered to obtain a leachate and a copper-nickel removal leaching residue. The leachate enters the crude nickel sulfate preparation process system, and the leachate is cooled and crystallized to separate and recover nickel sulfate;

[0048] (2) The copper-nickel removal leaching residue in step (1) is added to a Kaldo furnace for smelting and blowing reactions; the smelting temperature is 900 °C and the time is 6 h. When the silver content in the smelting slag is <0.2%, slag discharge treatment is started; the blowing temperature is 1200 °C and the blowing time is 2 h;

[0049] (3) When the precious metal alloy content ≥98% and the content of other impurities Cu + Ni <2% during the pyrometallurgical process in step (2), the molten precious metal alloy is subjected to water quenching treatment, and the temperature of the water used for water quenching is 0 °C;

[0050] (4) After the water quenching in step (3) is completed, the granulated alloy material is subjected to chlorination leaching to obtain silver chloride and a silver separation filtrate. After chlorination acid leaching, the silver content in the silver separation filtrate is <0.1%;

[0051] The specific method for chlorination leaching is as follows: The granulated alloy material is subjected to chlorination leaching with a liquid-solid ratio of 6:1, an acidity of 2 mol / L, a sodium chlorate addition amount of 18% of the weight of the alloy material, a leachate temperature of 80 °C, and stirring is carried out throughout the process;

[0052] (5) Fire-reduction smelt the silver chloride produced in step (4), cast it into silver anode plates, and further electrolytically refine to prepare silver powder. Return the silver anode slime to the alloy material after water quenching;

[0053] The method for fire-reduction smelting the silver chloride is as follows: Add sodium carbonate and iron powder to the silver chloride. The mass ratio of silver chloride, sodium carbonate, and iron powder is 5:2:1. After mixing evenly, perform reduction smelting at a furnace temperature of 1050°C. The silver chloride is reduced to metallic silver, and other impurity elements enter the slag and float on the metal liquid surface;

[0054] (6) Perform gold separation on the silver separation filtrate produced in step (5) to separately prepare gold sand and precious metal concentrates containing platinum, palladium, etc., and further purify them to prepare high-purity gold, platinum, and palladium products.

[0055] Example 3

[0056] A method for treating high-nickel and high-PGM anode slime is specifically operated as follows:

[0057] (1) Place a dilute sulfuric acid solution with a concentration of 300 g / l and pre-leached anode slime in an autoclave according to a liquid-solid ratio of 5:1. Apply pressure and heat. The temperature is 140°C, the pressure is 0.9 MPa, and oxygen is introduced as an oxidant. The oxygen flow rate is 20 Nm 3 / h to dissolve elements such as copper and nickel in the anode slime. Filter the obtained slurry to obtain leachate and copper-nickel removal leached residue. The leachate enters the crude nickel sulfate preparation process system. Cool and crystallize the leachate to separate and recover nickel sulfate;

[0058] (2) Add the copper-nickel removal leached residue in step (1) to a Kaldo furnace for smelting and blowing reactions; the smelting temperature is 950°C, the time is 4 h. When the silver content in the smelting slag is <0.2%, start slag discharge treatment; the blowing temperature is 1150°C, and the blowing time is 6 h;

[0059] (3) When the precious metal alloy content in the fire smelting process in step (2) is ≥98% and the content of other impurities Cu + Ni is <2%, perform water quenching treatment on the molten precious metal alloy. The temperature of the water used for water quenching is 30°C;

[0060] (4) After the water quenching in step (3) is completed, perform chlorination leaching on the granulated alloy material to obtain silver chloride and silver separation filtrate. After chlorination acid leaching, the silver content in the silver separation filtrate is <0.1%;

[0061] The specific method for chlorination leaching is as follows: Perform chlorination leaching on the granulated alloy material. The liquid-solid ratio is 8:1, the acidity is 2.5 mol / L, the sodium chlorate addition amount is 16% of the weight of the alloy material, the leachate temperature is 85°C, and stirring is carried out throughout the process;

[0062] (5) subjecting the silver chloride produced in step (4) to pyrometallurgical reduction smelting and casting into silver anode plates, further subjecting the silver anode mud to electrolytic refining to prepare silver powder, and returning the silver anode mud to the alloy material after water quenching;

[0063] The method of pyrometallurgical reduction smelting of the silver chloride is as follows: sodium carbonate and iron powder are added to the silver chloride, the mass ratio of the silver chloride, sodium carbonate and iron powder being 5:2:1, and after being evenly mixed, reduction smelting is performed at a furnace temperature of 1150° C., the silver chloride is reduced to metallic silver, and other impurity elements enter the slag and float on the metal liquid surface;

[0064] (6) subjecting the silver separation filtrate produced in step (5) to gold separation to prepare gold sand and precious metal concentrates containing platinum, palladium, etc., respectively, and further purifying them to prepare high-purity gold, platinum, and palladium products.

[0065] Comparative Example 1

[0066] Compared with Example 1, the water quenching step is omitted, and the rest is the same as Example 1.

[0067] Without the water quenching process, the precious metal alloy produced by the Kaldo furnace cannot be directly used as a silver anode plate for the electrolysis process, and the chlorination acid leaching is used to separate silver from gold and PGM elements. The precious metal alloy produced by the Kaldo furnace is a block-like object, and the chlorination acid leaching process to complete reaction is very slow and ultimately cannot be completely reacted.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for treating high-nickel and high-PGM anode slime, characterized in that: It includes the following steps: After mixing high-nickel and high-PGM anode slime with dilute sulfuric acid, pressurize and heat it, and at the same time introduce oxygen into the mixed solution for oxidation treatment to dissolve copper and nickel elements therein. After the reaction is completed, separate the solid and liquid to obtain copper and nickel-free leaching solution and copper and nickel-free leaching residue; Smelt and convert the copper and nickel-free leaching residue. When the precious metal content therein is ≥98%, carry out water quenching treatment to obtain granulated alloy materials; Carry out chlorination leaching on the granulated alloy materials to obtain silver chloride and silver separation filtrate; Carry out pyrometallurgical reduction smelting on the silver chloride and cast it into a silver anode plate for electrolytic refining to prepare silver powder; Carry out chlorination acid leaching treatment on the silver separation filtrate until the silver content in the silver separation filtrate is <0.1%, and then carry out gold separation treatment to obtain gold sand and precious metal concentrate; Purify the precious metal concentrate to obtain high-purity gold, platinum and palladium.

2. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: The concentration of the dilute sulfuric acid is 300 - 450 g / l.

3. The treatment method of high-nickel and high-PGM anode slime according to claim 1, wherein: The temperature of the oxidation treatment is 140 - 170 °C, the pressure is 0.7 - 0.9 MPa, and the time is 10 - 20 h.

4. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: The temperature of the smelting is 900 - 1000 °C, the time is 2 - 6 h, and when the silver content in the smelting slag is <0.2%, start the slag discharging treatment; The temperature of the converting is 1100 - 1200 °C, and the time is 2 - 8 h.

5. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: Use the copper and nickel-free leaching solution to prepare crude nickel sulfate.

6. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: The method for using the copper and nickel-free leaching solution to prepare crude nickel sulfate is: cool and crystallize the copper and nickel-free leaching solution, and separate and recover nickel sulfate.

7. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: The temperature of the water for water quenching is 0 - 50 °C.

8. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: The specific method for carrying out chlorination leaching on the granulated alloy materials is: carry out chlorination leaching on the granulated alloy materials, with a liquid-solid ratio of 6 - 8:1, an acidity of 2 - 3 mol / L, the sodium chlorate addition amount being 12 - 18% of the weight of the alloy materials, the leaching solution temperature being 75 - 90 °C, the hydrochloric acid concentration being 25 - 32%, stir to obtain silver chloride and silver separation filtrate, and after chlorination acid leaching, the silver content in the silver separation filtrate is <0.1%.

9. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: The method for carrying out pyrometallurgical reduction smelting on the silver chloride is: add sodium carbonate and iron powder to the silver chloride, mix evenly, and carry out reduction smelting at a furnace temperature of 1050 - 1250 °C.

10. The treatment method of high-nickel and high-PGM anode slime according to claim 1, characterized in that: Recover the silver anode slime generated after electrolytic refining of the silver anode plate to prepare silver powder into the alloy materials after water quenching.

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